


Ritsuka Fujimaru and the Art of Not Shutting the Fuck Up

by kyasuu



Category: Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: Futanari, Gender Neutral Pronouns, Other, Porn With Plot, Porn and Humor, Terrible Dirty Talk, but its very hard to be stay good at sex, does it still apply if the plot is dedicated to getting the porn, i am basically projecting onto them here bc i too want to fuck cu chulainn, i am going to be honest here this is more smutty humor than humorous smut, i turned adult years old today so clearly the correct way to celebrate is to write terrible porn, in which cu is very good at sex, like actually really bad, oh if it wasnt obvious already cu bottoms, ritsuka is afab but uses they pronouns, sorry if youre not here for that im a thirsty top, this one is for you shitlord supreme, when everything that comes out of your partner's mouth is unsexy as fuck
Language: English
Status: Completed
Published: 2019-09-28
Updated: 2019-09-28
Packaged: 2020-10-29 19:34:01
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,010
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20801798
Author URL: https://archiveofourown.org/users/kyasuu/pseuds/kyasuu
Summary: In which Ritsuka Fujimaru wants a dick in the name of fucking their Servant without a strap-on. It goes as well as one would expect.





	Ritsuka Fujimaru and the Art of Not Shutting the Fuck Up

**Author's Note:**

> This is not my first time writing porn but it's my first time posting it properly. Please be gentle
> 
> I hope you enjoy, this is mostly for laughs instead of thirst
> 
> let me know if i missed tagging something!

Cú pants as Ritsuka pushes in, the noises muffled by the pillow he’s buried his face in. “Fuck,” says Ritsuka, for more than one reason. “That’s hot.  _ You’re _ hot.”

“And yer slow,” Cú complains into the pillow, wriggling his ass against the strap-on, trying to get Ritsuka to push in more. They just flick his ass, like they’re scolding him. “Come  _ on _ , Master,” he whines, dragging out the word longer than necessary. 

“As ridiculous as it sounds, I don’t want to actually hurt you,” Ritsuka points out exasperatedly, though they do admit they kind of just enjoy watching Cú struggle miserably. So what, they’re a bit of a sadist. Sue them.

“Yer hurting me  _ now _ with how fucken sl—” Without warning, Ritsuka pushes the rest of the way in and Cú’s sentence is broken off by a string of unintelligible noises they’re pretty sure are curse words.

“I hate ya so much,” Cú moans. Ritsuka isn’t sure if it’s a pleasure moan or an annoyed moan, only that it’s probably both and it’s really hot regardless. 

“No, you don’t. I have a dildo up your ass and you haven’t killed me yet,” Ritsuka points out, just because they’ve never claimed to be a good person. 

“Yer godawful dirty talk aside, just fucken  _ move _ before I actually kill ya,” Cú growls, turning his face to glare up at them. Ritsuka just grins, and rolls their hips against Cú’s ass. That elicits a nice, satisfying shudder from their Servant.

“Well, that’s enough of bullying you,” Ritsuka laughs, and their hands come to settle around Cú’s hips, tightening around them slightly to get a better grip. “You won’t be walking right tomorrow.”

* * *

Ritsuka runs a hand through Cú’s hair, which had come loose at some point, as he sleeps in their lap. Much to their annoyance, they’re still horny, but they suppose that’s the downside of just using a strap-on. They can just jack off later or ask Cú to do something about it; normally he does, but Ritsuka had been pretty relentless today. 

Still, it’d be nice to be able to actually get something out of topping other than a metaphorical boner and wet panties. It sucks because that’s Ritsuka’s preference, and yet, because of a lack of a dick…

They blink, suddenly reminded of something. Hadn’t Scáthach said she could… do something like that? She’s pretty skilled in runes, and she could create a lot of things on that island… But is it really worth bothering her for?

Ritsuka takes one look at their crotch and the (bad) decision is made. 

* * *

“You are going to ask me for something stupid,” says Scáthach the moment she opens the door and sees Ritsuka, just a second before they’re about to knock. 

“Hi?” Ritsuka says, with a nervous laugh. 

Scáthach just stares at them, unimpressed, for a few moments before opening the door further. “Come in,” she orders instead of invites. “What is it?”

Ritsuka opens their mouth, and then closes it. How do you even ask,  _ Hey, can you make me a dick with magic so I can fuck someone properly? _ They hadn’t actually thought this far, which, judging from Scáthach’s arched eyebrow, was a bad move on their part. 

“Your runes,” Ritsuka blurts out. “On the island, y-you said…” They struggle for a few moments before they give up and point downwards. 

Scáthach looks speechless for a few moments. “Excuse me,” she says, pressing a hand to her face. “Please tell me I am misunderstanding. You want me to create an artificial penis for you with my runes.”

Ritsuka blushes. “Y-yes?”

The hand over her face slowly drags downward. “Presumably, this is to make sexual relations with my stupid student more enjoyable,” she continues, and Ritsuka is not sure how they feel about having their sexual exploits dragged. 

Ritsuka just coughs, because they don’t dare speak up against Scáthach. 

“Did Setanta put you up to this?” Scáthach inquires with a sigh, removing her hand from her face. Instead, she crosses her arms over her chest. Ritsuka just shakes their head and smiles nervously. 

“Good. I would have smacked him if he did.” Scáthach fixes Ritsuka with a very unimpressed look. “The answer is  _ no _ . Ask someone else.”

After that, Ritsuka is very unceremoniously kicked out of Scáthach’s room. They think for a moment. Who else could they ask about this…? 

Then, they realize they’re being stupid. 

* * *

“Merlin,” says Ritsuka, with all of the intensity (and desperation) of a horny bastard unable to properly get themself off as they open said magus’s door without knocking. Merlin jolts as they forcibly turn him around, their face terrifyingly close. 

“Ah, Ritsuka,” he greets with a bland smile. “What do you ne—”

“I am,” Ritsuka begins, “horny. And I want a dick.”

Merlin blinks, mouth remaining open for a moment as he just stares at them. He seems to be stunned speechless. “Pardon,” he says, slowly shutting his mouth like he’s just noticed it’s not closed. “Could you say that again?”

“I am horny, and I want a dick,” Ritsuka repeats. “Please.”

Surreptitiously shutting the laptop Chaldea had provided behind him, Merlin laughs awkwardly. “Well, Ritsuka, when I offered to give love advice, this isn’t quite what I had in mind.”

“I’m begging you,” Ritsuka says, putting their hands together almost in prayer. “I know you’ve done it for Artoria before. You can do it for me, right?”

“I suppose I could,” Merlin allows with a sigh. He props his face on his cheek, looking up at them. “I’m assuming this is for your… thing with Cú Chulainn?”

“The thing where we fuck, yes.”

“Then no.” Merlin beams up at them despite their expression darkening. “I’m quite busy, and unless it’s necessary for the survival of humanity, I won’t bother.”

“Busy catfishing people?” Ritsuka sulks. They huff, heaving a deep sigh. “Oh, well…”

* * *

“I went around and asked for a dick today,” Ritsuka says out of the blue, when it’s just them and Cú in their room. Cú makes a choking noise as Ritsuka just eats another potato chip. 

“Are ya gonna give me any context on that or…” Cú asks, and to Ritsuka’s delight, he sounds like he’s sulking. They make a cooing noise at him, and he just glares half-heartedly. He’s so cute when he’s jealous. 

Ritsuka expresses this sentiment out loud. “You’re adorable when you get all possessive,” they tease, reaching out with potato chip fingers and pinching his cheek. He makes a disgusted expression when potato chip dust gets on his face. 

“Shut  _ up _ ,” he groans, scrubbing at his cheek. “Get to the point.”

“I asked Scáthach and Merlin to give me a dick, but both of them said no,” Ritsuka says with dismay. Cú makes another choking noise. “It would be so much more fun with an actual dick. Being born with a coochie fucking sucks.”

“Okay, first of all, don’t call it a fucken coochie,” Cú says when he’s no longer making a drowning impression. “That’s gross and unsexy. I put my mouth there. Second of all, what the fuck? Third of all, ya could’ve asked  _ me _ .”

Ritsuka pauses, a chip hovering in the air right in front of their mouth. “Fuck, I  _ am _ stupid,” they say after a long moment of silence, and then shove the chip in their mouth. “Does that mean you’re offering?”

Cú opens his mouth, like he’s about to agree, before he pauses, like he’s reconsidering that agreement. Ritsuka just crunches loudly on their potato chips, waiting for him to come up with a response. 

“We can try it,” Cú says finally. He sounds vaguely apprehensive, which is new. At the gleam in Ritsuka’s eyes, he adds, “I’m not giving ya a permanent dick, Master.”

Ritsuka grimaces. “Fuck, I hope not. I don’t want to even know how that’d work when I’m on my period, and I’d rather not find out.” They smile hopefully at him, licking the potato chip dust off their fingers. “Tonight?”

“…tonight.”

* * *

“This is probably the most egregious abuse of an ancient magical superpower  _ ever _ ,” Ritsuka says. 

“Yer the one who asked for it,” Cú points out dryly. He seems to be blushing furiously, but that might just be wishful thinking from the light cast from his runes. Ritsuka just waits patiently as Cú finishes up and looks away with mild embarrassment. 

Ritsuka stares down at their new dick. “I have several questions,” they begin, coming to a few revelations about their Servant. “Are you, by any chance, a size queen? Or is this your extremely roundabout way of saying I have tremendous big dick energy?”

“Oh my  _ gods _ ,” Cú groans, and covers his face with his hands. It does nothing to hide the burning red in his ears, which is adorable and fucking hilarious. “Which answer is less humiliating?”

“I’m taking that as a yes to both,” Ritsuka says. Cú swats them on the arm, but he’s laughing. 

“It’s the second one, okay?” Cú huffs. “The rune is just an incomplete sex change. I can’t control how big yer dick happens to be.” He huffs. “Besides, ya looked Goetia in the face and swung a shield at him. That’s pretty big BDE.”

“Aww,” Ritsuka coos, touched. “That’s so sweet.” They press a chaste kiss to his cheek. “I can’t believe you said that to defend yourself over giving me a giant dong.”

Cú looks like he doesn’t know whether to laugh or get annoyed, and it results in a weird, cut off coughing noise. “Look, ya have yer big dick now,” he says impatiently. “Are ya gonna use it, or just admire it until it goes away?”

“Does helicoptering it count as using it?” Ritsuka asks, grinning as Cú leans forward, laughing helplessly into their shoulder. “I’m new to this whole having-a-dick business, man! Help me out here.”

“I’ll help ya out alright,” Cú says, his voice dropping an octave and breath warm against Ritsuka’s bare shoulder. They smirk, pressing a cheek against Cú’s messy locks. 

“Go for it,” they murmur into his hair. A hand ghosts over their bare thighs, warm but barely there, and drifts between them. Ritsuka stiffens when a hand wraps around the base of their cock. “Oh, that’s  _ weird _ ,” they say, a little breathless. 

“Bad weird or good weird?” Cú asks, lifting his head up to look at them properly. He tilts his head to the side a little, red eyes searching theirs. 

“Mm… can’t figure that out yet,” Ritsuka says, baring their teeth in a smile. “Why don’t you keep going and help me find out?”

“With pleasure.” Cú’s hand moves up, and Ritsuka bites their bottom lip as pleasure jolts through them, feeling heat pool in their belly and cheeks. “That fine?” 

“Very fine,” Ritsuka answers after a moment make sure their voice is steady. “Very,  _ very _ fine.” Cú chuckles a little, maintaining his slow pace. Normally, Ritsuka would be infuriated by him trying to be a fucking cocktease (literally this time) but they’re a bit grateful for that right now. It’s taking a bit of time to grow accustomed to their new, er, appendage. 

Eventually, Cú bends down so his face is level with Ritsuka’s dick. Ritsuka’s throat goes dry at the sight of Cú smirking up at them between their legs. “Don’t say anything that’s gonna make me wanna bite yer dick off,” he warns, and Ritsuka snorts, amused. That threat doesn’t scare them at all, even when Cú reveals his sharp canines.

“Get on with it, puppy,” they tease, and Cú just glares at them half-heartedly. 

“Did ya even hear what I just fucken said,” he grumbles, but nonetheless brings his mouth to Ritsuka’s cock, licking a long stripe up to the head, and Ritsuka’s toes curl and their breath hitches. It feels completely different from getting eaten out, yet oddly similar.

Cú’s tongue swirls around the head of the dick before his lips come around it, tongue lapping at the slit, and Ritsuka allows a sharp breath to escape, bringing a hand to their mouth as they watch. “ _ Fuck _ ,” they curse when Cú sucks, not missing his smug expression as he lowers his mouth on Ritsuka’s dick. They don’t like that, and decide to punish him by opening their mouth. 

“Holy fuck,” they say breathlessly when Cú takes the whole thing down, the wet heat around their cock setting Ritsuka’s nerves alight. “Literally. Aren’t y-you like a demigod or s-something?” 

Cú sighs, or as much as he can with a dick down his throat, and Ritsuka manages a shaky grin at his exasperated look as he slowly lifts himself up. Even that is arousing, and Ritsuka bites the skin of their hand to keep themself from making noise. “Ya  _ really _ need to work on yer dirty talk,” he complains, even though he was very happily sucking cock a moment ago. 

“You wouldn’t have me any other way,” Ritsuka protests. “My dirty talk is the best, jackass. Also, I think this is the gayest shit we’ve ever done.” 

“Please shut the fuck up,” Cú bitches, and before Ritsuka can reply to that, shuts them up pretty effectively by putting their dick back in his mouth. 

“No, you,” Ritsuka says anyway, because they’re a little shit, and Cú sucks harder, just to get them to keep their mouth occupied with anything that  _ isn’t  _ a complete turn off.

It more or less works, because Ritsuka just spends the next few minutes cursing, since Cú’s as good at sucking dick as he is eating pussy, which is totally unfair. And then Ritsuka curses for a different reason as Cú stops, pulling away. “Oh, fuck you,” they groan as Cú sits up, looking far too pleased with himself. 

“That’s the plan, Master.” He grins, showing his sharp teeth, and waggles the bottle of lube in his hand. Ritsuka isn’t sure when he’d gotten that in the first place. “How do ya want me tonight?”

“Doggy style?” Ritsuka asks, snickering when Cú rolls his eyes, looking like he’s about to shove the bottle of lube down their throat. “How about a ride?”

“Oh, so I’m doing all the work,” Cú says, snorting. “Fine with me.” He brings the bottle of lube to his mouth, unscrewing the cap with his teeth. It’s completely unnecessary, but Ritsuka knows he’s doing it to give them a show. And it’s working, because that is hot as fucking hell. 

(They know they have a fang kink. Cú knows it too, and he abuses that knowledge to an unfair degree.)

“Keep yer trap shut,” Cú warns as he pours lube over his fingers. “If ya say  _ anything _ completely unsexy I am gonna jack off and leave ya alone.”

Ritsuka almost says something anyway, but they also don’t want to die of blue balls the first time they actually have a dick to use, so they don’t say anything as Cú opens himself up, deliberately shifting himself so they can see. They swallow, throat dry. Cú’s threat was largely pointless, because it’s not like they could talk right now either. 

It doesn’t take long, and Cú pours more lube over his hand and reaches out to Ritsuka’s dick. They shiver at the coolness of the viscous liquid, but Cú’s fingers moves much more easily over it. “Hey, yer actually quiet for once,” Cú pants as he moves over to Ritsuka, almost straddling their waist. He lines their cock against his entrance, and slowly moves downward.

“I didn’t w-want,” Ritsuka gasps, a little shocked by the  _ sensation _ , “to get cucked out of being able to actually use my dick.”

Cú glares halfheartedly at them, because it’s sort of hard to glare at someone who has a ginormous penis up your ass. As it is, he looks caught between turned off and turned  _ on _ . “I can still make good on that threat,” he points out.

“ _ Sure _ you can,” Ritsuka taunts, and bucks upward with their hips. Cú grits his teeth, sucking in a sharp breath. “I literally have a dick up your ass, and you put it there yourself.”

“I have no idea how, but ya somehow manage to make  _ everything _ sound completely unattractive.” Cú’s words don’t match what his body says, because he’s clenched tightly around Ritsuka’s dick, a hot, pressing heat around it. One look downward, and Ritsuka can see his own cock hard as Cú lifts himself off and slams back down. 

Ritsuka chokes out a breath at the sensation, hearing Cú’s own labored breathing in their ear as he braces himself against their shoulders, hands gripping them as he sets a brutal pace. 

“A t-turn-off, huh?” Ritsuka demands breathlessly, not wanting to be outdone, and wraps a hand around Cú’s dick. “What’s t-this guy saying, then, huh?”

“It’s not saying anything,” Cú growls, “because it’s a fucken penis, and it can’t talk.” Ritsuka grins, taking probably too much enjoyment out of the annoyance and arousal clear on Cú’s face; it’s a good mix they find extremely attractive. While Ritsuka wishes they could say they’re just bad at being sexy on purpose, they can’t help it.

They move their hand as Cú’s movements become more erratic as he approaches his limit, completely uncoordinated with Ritsuka’s own frantic, messy movements. Ritsuka buries their face in Cú’s bare shoulder, muffling their voice as they approach climax. “Coming,” they pant, which is the only warning they’re able to give. Even after that, Cú doesn’t stop, chasing his own orgasm relentlessly, but it doesn’t take long before he comes too.

Ritsuka rests their sweaty forehead against Cú’s shoulder, breathing heavily and just taking a few long moments to catch their breath. “Definitely a good weird,” they mumble, and Cú gives a low rumbling chuckle that Ritsuka feels more than hears.

“Glad ya had fun,” he says, making no move to get off Ritsuka’s dick. They figure it’ll disappear soon, so there’s no reason for him to. 

Ritsuka smiles against Cú’s skin. “No homo, by the way,” they add cheekily. Cú heaves a deep, exasperated sigh that Ritsuka feels against their neck, and they snicker loudly.

**Author's Note:**

> i cant believe the first fic ive finished in like a year is a fic dedicated to expressing my desire to smash cu chulainn


End file.
